1. Field of the Invention
This invention relates generally to orthodontic treatment and appliances, and is more particularly concerned with a device that can be attached to a fixed subperiosteal or intra bony anchor, and from which pushing or pulling forces can be exerted to move teeth and correct malocclusions.
2. Discussion of the Prior Art
The use of fixed, immovable bony anchors as rigid objects from which to exert forces to move teeth has been considered in orthodontics for more than twenty years. See, for example, Sherman, A. J., "Bone reaction to orthodontic forces on vitreous carbon dental implants", "American Journal of Orthodontics", vol. 74, p. 79, 1978, and Smith, J. R., "Bone dynamics associated with the controlled loading of bioglass-coated aluminum oxide endosteal implants," American Journal of Orthodontics, vol. 76, p. 618, 1979. These early studies used animal models, and it was not until 1983 that their use was demonstrated in clinical orthodontics. See Creekinore, T. A. and Eklund, M. K., "The possibility of skeletal anchorage", Journal of Clinical Orthodontics, vol. 17, p. 266, 1983. Thereafter, additional reports of the use of a bony anchor from which to exert forces to move teeth have appeared. See, for example, Turley, P, K., Gray, D. W., Kean, L. J. and Roberts, E. W., "Titanium endosseous and vitallium subperiosteal implants as orthodontic anchors for tooth movement in dogs", Journal of Dental Research, vol. 63A, p. 334, 1984, and Goodacre, C. J., "Rigid implant anchorage to close a mandibular first molar extraction site", Journal of Clinical Orthodontics, vol. 18, p. 693, 1994. More recently, interest has shifted to subperiosteal anchors as described by Block and Hoffman in U.S. Pat. Nos. 5,066,224 and 5,538,427, and in the article "A new device for absolute anchorage for orthodontics", Journal of Orthodontics and Dentofacial Orthopedics, vol. 107, p. 251, 1995.
All of the above mentioned anchor systems utilize either endoseous or subperiosteal placement and afford rigid, immovable objects from which forces can be exerted so teeth can be moved forward, backward, upward, downward, and sideways. All such anchors will be hereinafter referred to as bony anchors. However, the surgical placement of these anchors in numerous areas of the mouth is frequently very difficult because of limited access, or the presence of nearby roots, nerves, and blood vessels. Additionally, the means of attaching to these anchors is technically difficult, and complicated mechanical objects are required to facilitate tooth movement and orthodontic corrections. (an example see patent application of Devincenzo, application Ser. No. 08/948,731 filed Oct. 10, 1997.)
It is technically difficult to work in the back and roof of the mouth. It is easy to work in the front and along the sides of the mouth opposite the upper teeth.